Table 1 Thresholds and accuracies of different thresholding methods
Images | Optimal threshold | Otsu method | 2-D Otsu method | 2-D maximum entropy | This paper method | ||||
|---|---|---|---|---|---|---|---|---|---|
Threshold | A th (%) | Threshold | A th (%) | Threshold | A th (%) | Threshold | A th (%) | ||
Figure 5a | 138 | 84 | 60.9 | (84,85) | 61.2 | (101,108) | 75.7 | 138 | 100.0 |
Figure 6a | 140 | 115 | 82.1 | (115,131) | 87.9 | (118,118) | 84.3 | 145 | 96.4 |
Figure 7a | 100 | 79 | 79 | (80,80) | 80.0 | (122,105) | 86.5 | 99 | 99.0 |
Figure 8a | 135 | 104 | 77.0 | (104,105) | 77.4 | (138,138) | 97.8 | 137 | 98.5 |
Figure 9a | 125 | 105 | 84.0 | (105,106) | 84.4 | (123,123) | 98.4 | 131 | 95.2 |
Figure 10a | 121 | 115 | 95.0 | (115,116) | 95.5 | (153,153) | 73.6 | 126 | 95.9 |
Figure 11a | 155 | 85 | 54.8 | (85,84) | 54.5 | (112,112) | 72.3 | 146 | 94.2 |
Figure 12a | 143 | 92 | 64.3 | (92,94) | 65.0 | (97,103) | 69.9 | 139 | 97.2 |
Average | – | – | 74.7 | – | 75.7 | – | 82.3 | – | 97.1 |